Just about 100%. I don't think this is so much a theory as an analogy.

Ian


"Roger Worden" wrote in message
m...
In the Jan. 2004 issue of Model Aviation, in the Radio Control Soaring
column, Real Smart Guy candidate Mike Garton proposes a "condensation
analogy" to suggest places to look for thermals to trigger. Imagine water
condensing on a ceiling: it drips first from the low spots or tiny bumps.
Now imagine heated, but relatively stable, air along the ground. If it's
"trying" to rise, might it not "drip up" first from the higher spots,
little
hills, even trees? If it's moving slowly horizontally, and encounters a
tree
line, it might be forced up enough to trigger a thermal. His experience
with
models supports the theory on the small scale. Does y'all's experience
support it at the larger scale?

Roger Worden

Same thing with sandy areas - the books say to avoid them like the
plague, but the sandy washes here in Arizona are also consistent
thermal sources - and like the ponds/tanks, are low discontinuities in
the local terrain. In this case, I'm sure it's not the sand that is
causing the thermal, my uneducated guess is that the wash channels (or
collects) the incipient themal until it gets big and strong enough to
break loose.

Any Real Smart Guys out there care to give us a serious possible
explanation for these effects? - or maybe we need to keep this to
ourselves and let the youngsters figure it out for themselves! Got to
keep a few tricks in our bags, you know, something about age and
experience beating youth and skill...

Kirk